Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis

PLoS One. 2015 Apr 27;10(4):e0124510. doi: 10.1371/journal.pone.0124510. eCollection 2015.

Abstract

Multiple sclerosis (MS) is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS). Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1) have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB). The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons
  • Biological Availability
  • Brain-Derived Neurotrophic Factor / metabolism
  • Choline O-Acetyltransferase / metabolism
  • Collagen Type IV / metabolism
  • Demyelinating Diseases / drug therapy
  • Demyelinating Diseases / pathology*
  • Disease Models, Animal
  • Encephalomyelitis, Autoimmune, Experimental / drug therapy
  • Encephalomyelitis, Autoimmune, Experimental / pathology
  • Mice
  • Multiple Sclerosis / drug therapy
  • Multiple Sclerosis / pathology*
  • Neurons / drug effects*
  • Neurons / pathology*
  • Paralysis / drug therapy
  • Paralysis / etiology
  • Permeability
  • Plasminogen Activator Inhibitor 1 / pharmacology*
  • Psychomotor Performance / drug effects

Substances

  • Brain-Derived Neurotrophic Factor
  • Collagen Type IV
  • Plasminogen Activator Inhibitor 1
  • Choline O-Acetyltransferase

Grants and funding

The authors’ work is supported in part by grants from the Ministry of Health, Labour and Welfare of Japan (Initiative to facilitate development of innovative drug, medical devices, and cellular and tissue-based products), from the Japan Science and Technology Agency (Adaptable & Seamless Technology Transfer Program through Target-driven Research and Development) and from the National Institute of Biomedical Innovation (Advanced Research for Medical Products Mining Progamme).